Conveyor Bridge Modifications

CLIENT: Agricultural Wet Feed Process Facility

PROJECT: Conveyor Bridge Modifications

BACKGROUND: 

The client selected ADF Engineering to perform structural and mechanical engineering services to upgrade their existing conveyor support bridge to add an additional conveyor as well as upsize all the existing ones.

CHALLENGES:

  • Severely undersized members
    The existing conveyor bridge was significantly under designed which presented unique challenges in the design phase because full replacement of the existing bridge would create challenges for the client’s shutdown timeframe. In order to strengthen the existing bridge the use of a truss was implemented tying the new addition of the top conveyor to the lower layer of steel.
  • Foundation design
    The client did not have footing information for the existing bridge pier, which presented a unique challenge in the approach that ADF needed to take in considering the design. A combined footing with steel spreaders was selected in order to increase resistance to overturning and spread the increased load over more area.
  • Strict Deflection Criteria
    Screw Conveyors have very sensitive internal components that bind up when the structure supporting the conveyor deflects past the appropriate limit. With severely undersized members, the client was having major reliability issues as the existing screw conveyors would require much more frequent maintenance, due to unforeseen excessive deflection on the magnitude of 7x to 8x higher than the maximum allowable. ADF Solved this problem in the redesign of the bridge by utilizing a truss, where the deflection is now a 1/10th of the maximum allowable deflection.

    3d image of a conveyor bridge remodeling

WORK COMPLETED:

ADF performed multi-discipline engineering services and completed Detail Design and construction phase assistance. This project layout was ultimately designed to benefit plant operation and maintenance. It was comprised of modification to the existing conveyor bridge and the expansion of the conveyor bridge to include a second level to support another conveyor.

Structural design of this new expansion included:

  • Laser scanning of the area to collect locations of all existing structures. These scans were used in conjunction with any available drawings to create a 3D model.
  • Develop the structural specifications and design drawings for the following items:
    • Bridge footings and pier modifications.
    • Modifications to the existing building line to enclose an area near the building.
    • Modifications to existing structural bents.
    • New interior platform to support new conveyor.
  • Construction phase assistance included:
    • Structural shop drawing review
    • Responding to RFIs and other construction related questions
  • Mechanical design of the Conveyor Bridge Modifications included:
    • Conveyor design specification
    • Spouting and slide gate design

SUMMARY:

Working with an existing structure is often far more difficult than working with a new structure, largely due to the constraints that the existing structure has. It is especially difficult to deliver a cost-effective solution that factors in construction cost and time. ADF is uniquely equipped to deal with these constraints largely due to level of experience amongst the team. Despite unique challenges and tight construction windows, the ADF team was able to design a solution that met the client’s needs and project objectives.

For additional information on Structural design for plants, please contact [email protected] or contact ADF Engineering.